Technical field
[0001] The present invention relates to a multi-layered plastic material having good odor
barrier properties and which is suitable to make packages, of the type produced by
welding and severing sheets or tubes of plastic material at spaced locations. The
multilayer material of the present invention is particularly suitable for making stand-up
refill pouches for odoriferous compositions such as laundry and household cleaning
compositions.
Background of the invention
[0002] Many and various forms of stand-up plastic containers used as packages for receiving
dry, powdered or granular commodities or even flowable products or liquids have been
extensively described in the art as well as materials used for making same.
[0003] Many of said plastic materials are in the form of multilayer materials comprising
different types of materials in order that a variety of demands on properties of such
laminates in many fields are met. For example, in the field of detergent packages
there are severe demands upon the properties of laminates including for example moisture
impermeability, gas impermeability, ultraviolet rays-intercepting property, water-proof
property, mechanical strengths, cost, flexibility and the like. It is actually very
difficult to satisfy such requirements by using a single material.
[0004] For example, European patent application number 93870067.1. discloses the use of
multi-layer laminations of plastic/paper material or laminates/coextrudates of any
plastic material well known in the art such as high and low density polyethylene (HDPE,
LDPE). Other materials can be chosen and added to laminates/coextrudates of high and
low density polyethylene as a function of the protection needed for the contained
product. In particular, for dry odoriferous compositions such as detergent compositions,
the package can be made of a multilayer material comprising polyethylene terephtalate
(PET) sandwiched between laminates/coextrudates of high and low density polyethylene.
[0005] Such a package made of multilayer materials comprising a layer of polyethylene terephtalate
possess good barrier properties, e.g. the perfume release through the walls of such
a package is minimum. However, laminates comprising polyethylene (PE) and polyethylene
terephtalate (PET) are not fully desirable as they are not recyclable after use, as
compared to similar laminates without polyethylene terephtalate. Furthermore, such
multilayer materials when used to manufacture packages have the drawback that they
present quality issues due to the presence of polyethylene terephtalate. Indeed, there
is a danger of braking associated with packages made of such laminates comprising
polyethylene (PE) and polyethylene terephtalate (PET) when they withstand high pressures
and/or violent shocks, e.g. when the consumer lets such a package fall on the floor.
This is because polyethylene terephtalate possesses low ductility at room temperature
and does not absorb the impact of a shock. Another drawback associated with such multilayer
materials is that they are expensive due to the presence of polyethylene terephtalate.
[0006] It is thus an object of the present invention to provide a packaging material that
uses materials offering odor barrier characteristics while conferring greater environmental
advantages to said packaging material. It is a further object of the present invention
to provide such a packaging material at lower cost.
[0007] It is another object of the present invention to provide a multilayer material, which
allow to make packages for dry or liquid odoriferous compositions, such as laundry
or household cleaning compositions comprising perfume, said multilayer material preventing
perfume release through said packages.
[0008] It is another object of the present invention to provide packages which withstand
high pressures and violent shocks without danger of braking.
[0009] It is yet another independent object of the present invention to provide a process
allowing for the manufacture of a multilayer material offering good odor barrier characteristics.
[0010] These objects are met by providing a multilayer material comprising at least a polyolefine-based
material and a perfume barrier layer. Said perfume barrier layer comprises a lacquer.
[0011] An advantage associated with the multilayer material of the present invention is
that said lacquer contained therein is compatible with printing. Indeed said lacquer
can be applied on conventional printing presses like flexographic or gravure, sandwiched
between other layers or as a frontal printing.
Summary of the invention
[0012] The present invention provides a multilayer material and packages made of a material
comprising said multilayer material and a method of making said multilayer material
in a manner to satisfy the aforementioned needs.
[0013] The present invention encompasses a multilayer material comprising at least a layer
of polyolefine-based material and a perfume barrier layer, said polyolefine-based
material comprises less than 25% by weight of the total multilayer material of post
consumer recycled plastic and said perfume barrier layer comprises a lacquer forming
mixture.
[0014] The present invention also encompasses a package, such as a stand-up refill pouch,
made of a material comprising the multilayer material according to the present invention.
Such a package being particularly suitable for containing an odoriferous composition,
such as fabric and/or household treatment compositions.
Detailed description of the invention
[0015] In order to make the invention more readily understood, reference will now be made
to the accompanying drawings, in which;
Figure 1 schemically illustrates the transverse structure of the preferred embodiment of the
multilayer material according to the present invention: the perfume barrier layer
is sandwiched between two layers of polyolefine-based material.
Figure 2 schemically illustrates the transverse structure of an embodiment of the multilayer
material according to the present invention: a layer of polyolefine-based material
and the perfume barrier layer.
Figure 3 is a perspective view of a refill pouch in accordance with the present invention
made of said multilayer material.
[0016] The multilayer material of the present invention comprises at least a layer of polyolefine-based
material and a perfume barrier layer, said polyolefine-based material comprising less
than 25% by weight of the total multilayer material of post consumer recycled plastic
(PCR).
[0017] As an essential feature the multilayer material of the present invention comprises
a layer of polyolefine-based material. By "polyolefine-based material" it is to be
understood herein that all different types of polyolefines well known in the art including
the polyolefine copolymers having olefinic monomers such as ethylene, propylene, butene,
and the like, are suitable. Preferred herein are polyethylenes such as low density
polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene
(HDPE) and the like. Such polyethylenes are known to those skilled in the art, for
example, LLDPE is commercially available from Dow under the trade name Dowlex®.
[0018] Said layer of polyolefine-based material is either a blended or/and a laminated or/and
a coextruded film. Preferred herein are the blended or laminated/coextruded films
comprising a low density polyethylene, a linear low density polyethylene, a high density
polyethylene, or mixtures thereof. Said films may have different thicknesses and densities
depending on their use. It is preferred herein to use polyolefine resin films with
the highest possible specific density, to minimize stretching of the films and thereby
also avoid that cracks appear in the lacquer. Said films of the present invention
so formed must have a minimum surface tension of 40 dyn/cm, preferably of 42 dyn/cm.
Indeed, different techniques may be used in order to improve the bond strengths of
said films including physical surface treatments, e.g. sand blasting, or chemical
surface treatments, e.g. corona discharging and/or application of a primer.
[0019] As another essential element the multilayer material of the present invention comprises
a perfume barrier layer. Said perfume barrier layer comprises a lacquer forming mixture,
said perfume barrier layer having a thickness of from 1 to 20 micrometers, preferably
of from 1.5 to 5 micrometers and most preferably of from 2 to 3 micrometers.
[0020] The perfume barrier layer according to the present invention comprises preferably
a two-component polyurethane system based on polyesterpolyols and polyisocyanates
(crosslinker) in combination with cellulose derivatives and/or polyvinylalcohol derivatives
as the lacquer forming mixture. Nitrocellulose is an example of suitable cellulose
derivatives to be used according to the present invention. Polyvinylbutyral is an
example of suitable polyvinylalcohol derivatives to be used according to the present
invention.
[0021] The lacquer forming mixture can additionally contain up to 5% by weight, based on
the total amount of the lacquer forming mixture, of plasticizers such as dialkyl phthalates
(with alkyl ≧ C4) and/or up to 5% by weight of a commercially available slip aid and/or
up to 10% by weight of a commercially available keton resin, for example one based
on acetophenone/formaldehyde. Examples of lacquer forming components suitable for
the use of the present invention are Flexoplastol ® 2KB-Lacquer 9A 918 920 or Flexoplastol
® 2KB-Lacquer 9A 919 817 commercially available from BASF Lacke + Farben AG, Stuttgart.
[0022] Suitable examples of crosslinkers in the lacquer forming mixture are oligomeric polyisocyanates
having average molecular weights of between 1200 and 2000, preferably based on hexamethylendiisocyanate
(HDI), toluylenediisocyanate (TDI) and/or 4,4'-diphenylmethandiisocyanate (MDI), for
example Crosslinker 9A 919 612 or Crosslinker 9A 910 226, both commercially available
from BASF Lacke + Farben AG, Stuttgart, which crosslinkers are 60% solutions in ethylacetate.
[0023] The lacquer forming mixture is usually dissolved in an inert organic solvent, preferably
in an ester, such as ethylacetate. The lacquer forming mixture can for example contain
the polyesterpolyol together with the cellulose derivatives and/or the polyvinylalcohol
derivative and the above mentioned optional additives in an 38% by weight solution
in ethylacetate and the polyisocyanate (crosslinker), for example, as a 60% solution
in ethylacetate, in a weight ratio of 100:10 to 100:35, preferably of 100:20 to 100:30
and most preferably of 100:25.
[0024] The resulting lacquer forming mixture having an average solid content of about 40%
to 45% can be diluted - dependent on the application process and equipment - by adding
further inert solvent such as ethyl acetate.
[0025] Said perfume barrier layer can be applied either on one of the two sides of the layer
of polyolefine-based material or on both. Preferably said barrier layer is applied
on the side being printed, thus on the side which will form the outside of a package
made of the multilayer material of the present invention.
[0026] The multilayer material of the present invention further comprises less than 25%
by weight of the total multilayer material of post consumer recycled plastic (PCR),
preferably less than 24% and more preferably less than 22%. Said PCR is incorporated
in said layer of polyolefine-based material. Said PCR has the advantage to be environmental
friendly.
[0027] In one embodiment of the present invention said multilayer material comprises a first
layer of polyethylene and a perfume barrier layer. Said first layer has a thickness
of from 30 to 200 micrometers, preferably of from 40 to 150 micrometers and most preferably
of from 50 to 100 micrometers. In said embodiment said first layer of polyethylene
is a coextruded film of LDPE/LLDPE/HDPE.
[0028] In a preferred embodiment of the present invention said multilayer material comprises
a first layer and a second layer of polyethylene and a perfume barrier layer being
sandwiched between said first and said second layer. In such a multilayer material
the print is optimally protected against rubs and the product contained in a package
made of such material. Said first layer of polyethylene on which the advertising messages
are printed constitutes the inside layer. Said second layer is translucent and constitutes
the outside layer. By "inside layer" it is meant herein the layer which will be on
the inside side of a package and by "outside layer" it is consequently meant the layer
which will be on the outside side of said package made of a material comprising the
multilayer material of the present invention. Preferred as first layer is a coextruded
film of LDPE/LLDPE/HDPE having a thickness of from 30 to 200 micrometers, preferably
of from 40 to 150 micrometers and more preferably of from 50 to 100 micrometers. Said
first layer further comprises an opacifiant such as titanium oxide. Preferred as second
layer is a coextruded film of LDPE/LLDPE having a thickness of from 20 to 50 micrometers,
preferably of from 25 to 40 micrometers.
[0029] All coating methods known and common for any person skilled in the art may be used
to attach the different layers of the multilayer material of the present invention.
The present invention is applicable to coating methods using adhesives and to any
lamination technique such as heat sealing lamination and extrusion lamination without
using any adhesive. Preferred herein is to use non-heat-sealing methods with adhesives
capable of achieving a sufficient tight attachment of the layers of the multilayer
material. The adhesive commonly used are polyurethane type resin adhesives alone or
with any solvent well known to those skilled in the art, such as ethylacetate.
[0030] The production of the multilayer material of the present invention is done on coating
machines. The perfume barrier layer is preferably applied on the printing press, preferably
coated or printed, before, during or after the printing process itself. The following
printing techniques can be used to apply said perfume barrier layer according to the
present invention: flexographic, gravure, frontal, offset, silk screen. Preferred
herein a first layer of polyethylene is unwinded and then the perfume barrier layer
of the present invention is printed or coated thereto on a first station of a printing
press and then inks are applied on top of said barrier layer using other stations
of a printing press. In the embodiment wherein said multilayer material comprises
a second layer said layer is adhesively laminated on top of the so formed coated/printed
first layer and the formed sandwich is cured to ensure complete crosslinking of said
perfume barrier layer and said adhesive.
[0031] The present invention also encompasses packages made of a material comprising a multilayer
material according to the present invention. Preferably said packages are made of
a material being in its totality the multilayer material according to the present
invention.
[0032] The packages of the present invention may be used as a stand-up refill pouch. This
satisfies environmental protection considerations as said pouch can be rolled up after
use thereby producing less waste. Such a stand-up refill pouch, as can be seen from
figure 3, is formed from a length of generally flat multilayer material according
to the present invention, the longitudinal edges of said length being connected together
by a longitudinal seal (1), and the opposite ends (2) and (3) of the tube so formed
being closed, wherein on one lateral side (5) only a portion of the plastic container
adjacent each of the said ends is folded inwardly so as to form a gusset (4). Such
a pouch will stand on the gusset when presented on the shelf. The straight top located
on the opposite side of the gusset in such a pouch is preferably provided with a printed
line to indicate to the consumer how to cut the pouch such as to ease and control
pouring to the appropriate refillable package. It is also known to produce such pouches
having two gussets located on each of their lateral sidewalls. Such pouches with two
gussets respectively located on each of their lateral sidewalls stand on their bottom
transverse seals.
[0033] The multilayer material of the present invention is a barrier for odoriferous compositions.
By "odoriferous compositions" it is to be understood herein compositions comprising
any ingredients having an odor including ingredients having a base odor being either
pleasant such as perfumes, or unpleasant, such as fertilizers. Said multilayer material
of the present invention is suitable to manufacture packages for containing different
types of products being either in a dry or in a liquid form such as, but not limited
to automatic dishwasher detergents, laundry detergents, softeners and/or hard surface
cleaners. More particularly, the package according to the present invention is adequate
to contain from conventional unconcentrated detergent products to so called "concentrated"
products where the amount of odoriferous ingredients such as perfume is higher as
compared to said unconcentrated products, this to obtain the same level of perfume
during use, e.g. in a wash solution. Indeed, the package according to the present
invention is adequate to contain for example a dry concentrated composition having
a bulk density above 600g/l, said compositions containing beaches such as percarbonate,
perborate as well as perfumes. The multilayer material of the present invention is
also suitable to be used in other fields such as food, beverage, fertilizers and the
like.
[0034] Multilayer material according to the present invention are illustrated in figures
1 and 2 through the transverse structure of said multilayer material.
Example 1
[0035] As can be seen from figure 1, the perfume barrier layer (10) is sandwiched between
a first (11) and a second layer (12) of polyolefine-based material. Said first layer
is a 75 micrometers coexfilm made out of LDPE, LLDPE and HDPE. Said first layer is
a white pigmented film. Said second layer is a 25 micrometers transparent coexfilm
made out of LDPE and LLDPE. Said perfume barrier layer is Flexoplastol® 2KB - Lacquer
9A 918 920 with Crosslinker® 9A 919 612 dissolved in ethylacetate in a weight ratio
of the lacquer forming component to the crosslinker of from 100:25. The thickness
of said barrier layer is 2-3 micrometers.
[0036] In this example the perfume barrier layer (10) is coated onto said first film (11)
on the first station of a Flexographic printing press, inks (14) are applied on top
of said barrier layer using the other stations of the printing press. Said first film
has a minimum surface tension of 40 dyn/cm (corona treated film) this to obtain good
bonding of the perfume barrier layer and inks to said film. The perfume barrier layer
is applied by using a very fine Anylox® roller to have the coating as uniform as possible
and the weight in wet stage is 5 - 6 g/sqm which corresponds to +/- 2 g/sqm in dry
stage. After drying said second film is adhesively laminated on said coated first
film. As adhesive a polyurethane based adhesive is used. The perfume barrier layer
and print are in sandwich.
[0037] This multilayer material is used to produce gusseted refill pouches for detergent
powders comprising odoriferous compounds such as perfume. The perfume release through
the walls of such a refill pouch made of the multilayer material according to the
present invention is reduced as compared to commercially available pouches made for
instance only of polyethylene.
Example 2
[0038] As can be seen from figure 2, the perfume barrier layer (20) is applied onto a layer
(21) of a polyolefine-based material. Said layer is a 70 micrometers coexfilm made
of LDPE, LLDPE, HDPE and further contains 24 % of PCR. The perfume barrier layer is
Flexoplastol® 2KB - Lacquer 9A 919 817 with Crosslinker® 9A 919 612 dissolved in ethylacetate
in a weight ratio of the lacquer forming component to the crosslinker of from 100:25.
The thickness of said barrier layer is 2-3 micrometers
[0039] The perfume barrier layer (20) is applied on said film (21) on the first station
or on the last station of a frontal printing press, inks (14) are also applied using
the other stations of the printing press. Said film has a minimum surface tension
of 40 dyn/cm (corona treated film) this to obtain good bonding of the barrier layer
and inks to said film. The perfume barrier layer is applied by using a very fine Anylox®
roller to have the coating as uniform as possible and the weight in wet stage is 5
- 6 g/sqm which corresponds to +/- 2 g/sqm in dry stage. The perfume barrier layer
and print constitute the outside side of said film and will be located on the outside
side of a package made of such a material.
[0040] This multilayer material is used to produce gusseted refill pouches for detergent
powders. The odor release through the walls of said refill pouch made of the multilayer
material according to the present invention is reduced as compared to commercially
available pouches made for instance only of polyethylene.
1. A multilayer material comprising at least a layer of polyolefine-based material and
a perfume barrier layer, characterized in that said perfume barrier layer comprises
a lacquer forming mixture and that said polyolefine-based material comprises less
than 25% by weight of the total multilayer material of post consumer recycled plastic.
2. A multilayer material according to claim 1 wherein said material comprises a first
layer of polyolefine-based material and wherein said polyolefine-based material is
polyethylene.
3. A multilayer material according to claim 2 wherein said polyethylene is a blended
or coextruded film comprising a low density polyethylene, a linear low density polyethylene,
a high density polyethylene, or mixtures thereof.
4. A multilayer material according to claim 3 wherein said blended or coextruded film
has a thickness of from 30 to 200 micrometers.
5. A multilayer material according to any of the preceding claims wherein said multilayer
material further comprises a second layer of polyolefine-based material, preferably
polyethylene and more preferably a blended or coextruded film comprising a low density
polyethylene, a linear low density polyethylene, a high density polyethylene, or mixtures
thereof, said perfume barrier layer being sandwiched between said first and said second
layers.
6. A multilayer material according to claim 5 wherein said first layer is a coextruded
film comprising low density polyethylene/linear low density polyethylene/high density
polyethylene and having a thickness of from 40 to 150 micrometers, preferably of from
50 to 100 micrometers and said second layer is a coextruded film comprising low density
polyethylene/linear low density polyethylene and having a thickness of from 20 to
50 micrometers, preferably of from 25 to 40 micrometers.
7. A multilayer material according to any of the preceding claims wherein said perfume
barrier layer comprises a lacquer forming mixture, said perfume barrier layer having
a thickness of from 1 to 20 micrometers, preferably of from 1.5 to 5 and more preferably
of from 2 to 3 micrometers.
8. A multilayer material according to claim 7 wherein said lacquer forming mixture is
a two-component polyurethane system based on polyesterpolyols and oligomeric polyisocyanates
in combination with cellulose derivatives and/or polyvinylalcohol derivatives.
9. A multilayer material according to claim 7 or 8 wherein said lacquer forming mixture
further comprises plasticizers, slip aids and/or ketones resins.
10. A multilayer material according to any of the claims 7 to 9 wherein said lacquer forming
mixture is diluted in an inert organic solvent, preferably in an ester.
11. A package made of a material comprising a multilayer material according to any of
the preceding claims.
12. A package according to claim 11 wherein said material in its totality is said multilayer
material.
13. A package according to claim 11 or 12 wherein said package comprises an odoriferous
composition.
14. A package according to claim 13 wherein said composition comprises a perfume, said
composition being preferably a dry detergent composition and more preferably a dry
concentrated detergent composition.
15. A package according to any of the claims 11 to 14 wherein said package is formed from
a length of said material, the longitudinal edges of said length being connected together
by a longitudinal seal (1), and the opposite ends (2) and (3) of the tube so formed
being also sealed, said pouch on one of its lateral sides (5) only comprises a portion
adjacent each of the said ends which is folded inwardly so as to form a gusset (4),
on which said pouch stands.